From ce748eaa65f2e9392ba82726503c8d994ffd6393 Mon Sep 17 00:00:00 2001 From: Eric Sandeen Date: Wed, 29 Jul 2015 11:53:31 +1000 Subject: xfs: create new metadata UUID field and incompat flag This adds a new superblock field, sb_meta_uuid. If set, along with a new incompat flag, the code will use that field on a V5 filesystem to compare to metadata UUIDs, which allows us to change the user- visible UUID at will. Userspace handles the setting and clearing of the incompat flag as appropriate, as the UUID gets changed; i.e. setting the user-visible UUID back to the original UUID (as stored in the new field) will remove the incompatible feature flag. If the incompat flag is not set, this copies the user-visible UUID into into the meta_uuid slot in memory when the superblock is read from disk; the meta_uuid field is not written back to disk in this case. The remainder of this patch simply switches verifiers, initializers, etc to use the new sb_meta_uuid field. Signed-off-by: Eric Sandeen Reviewed-by: Brian Foster Signed-off-by: Dave Chinner --- fs/xfs/libxfs/xfs_dir2_leaf.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/xfs/libxfs/xfs_dir2_leaf.c') diff --git a/fs/xfs/libxfs/xfs_dir2_leaf.c b/fs/xfs/libxfs/xfs_dir2_leaf.c index 106119955400..f300240ebb8d 100644 --- a/fs/xfs/libxfs/xfs_dir2_leaf.c +++ b/fs/xfs/libxfs/xfs_dir2_leaf.c @@ -160,7 +160,7 @@ xfs_dir3_leaf_verify( if (leaf3->info.hdr.magic != cpu_to_be16(magic3)) return false; - if (!uuid_equal(&leaf3->info.uuid, &mp->m_sb.sb_uuid)) + if (!uuid_equal(&leaf3->info.uuid, &mp->m_sb.sb_meta_uuid)) return false; if (be64_to_cpu(leaf3->info.blkno) != bp->b_bn) return false; @@ -310,7 +310,7 @@ xfs_dir3_leaf_init( : cpu_to_be16(XFS_DIR3_LEAFN_MAGIC); leaf3->info.blkno = cpu_to_be64(bp->b_bn); leaf3->info.owner = cpu_to_be64(owner); - uuid_copy(&leaf3->info.uuid, &mp->m_sb.sb_uuid); + uuid_copy(&leaf3->info.uuid, &mp->m_sb.sb_meta_uuid); } else { memset(leaf, 0, sizeof(*leaf)); leaf->hdr.info.magic = cpu_to_be16(type); -- cgit v1.2.3